An elderly woman entered my crowded train as I rode the New York subway a few weeks ago. By all appearances, I was a healthy 20-something who was expected to give up my seat. But hidden under my coat was an IV inserted into my arm, delivering antibiotics.

I could feel the dirty looks, but I was simply too weak to stand. The embarrassment and disappointment I felt in myself is still fresh today. I couldn’t perform that most basic act of subway etiquette and had to sit in my own self-loathing because I was suffering from one of the worst lung infections of my life.

I have cystic fibrosis. Mine is a genetic disease, CF for short, that produces thick mucus in the lungs that clogs the airways. It affects more than 30,000 Americans, according to the CF Foundation. The resulting infections and scarring from the disease will one day prove fatal for me, as it ultimately does for all CFers. As a guy I knew in college once said, “He’s going to drown in his own lungs!”

CF has gone from being a disease often thought of as pediatric to one that people commonly live with until their 30s and 40s. A lucky handful have made it into their 50s and beyond. I’m 29.

I was diagnosed at 4. Mom tells me that she fell to her knees in tears when she received the results. My father quickly went out and bought the family’s first video camera to document what they were sure were my last few days on Earth. Doctors told my parents not to expect to see me much beyond high school.

To most, cystic fibrosis is a vaguely familiar term, often discussed like a famous novel you don’t want to admit you haven’t read. For me, cystic fibrosis is every waking second of every day.

I missed a family member’s funeral because I was in the hospital, where I also watched Fourth of July fireworks another year. I ignored pneumonia so I could play my saxophone -- an instrument I had only begun playing to exercise my lungs -- at an important gig. At 11, I learned that a 16-year-old friend had died, and soon realized that our shared disease would one day conquer me, too.

I have felt like a burden to nearly everyone close to me, and fear that as time marches on and true sickness nears, that burden will only grow. I fear that in the later years of my life I will be weak and pathetic, and that I will further resent my body.

The disease installs a countdown clock overhead, not only to death but to the next infection, the next inopportune digestive moment, the next time a close friend or relative must adjust his life to help. There is no remission and no letup. There is just a team of your supporters who can qualify your life only with phrases such as “struggle,” “fight” or “defy.” Worst of all is the phrase, "He suffers from," rather than "He lives with." Unless I get hit by a salt truck hauling several tons of irony, I will lose and cystic fibrosis will win. There is no fighting, only stalling.

Until recently. Last month, Vertex Pharmaceuticals gained the support of a Food and Drug Administration advisory panel on its path toward approval of a new cystic fibrosis drug, Orkambi, a follow-up to the company’s breakthrough drug, Kalydeco. For some patients with a specific gene mutation that causes cystic fibrosis, Kalydeco has been as close to a cure as we have seen. But Kalydeco’s benefits reach only about 4 percent of the CF population. Orkambi is targeted at a different mutation that occurs in more than half of CF patients.

In 2014, I enrolled in a trial of this drug. Those of us on the outside looking in on the Kalydeco results were hoping for the same success with Orkambi. We got close. I got close. In recent months, I’ve spent days feeling better than I have in years. Other days reminded me that this is still cystic fibrosis, and we have a long way to go.

It’s a humbling notion to accept that I simply cannot live without medical intervention. As the countdown clock continues to wind down, I am hopeful that Orkambi and whatever Vertex intends to follow it with will prove to be the game changers CF patients have been waiting for.

Maybe one day I will be the elderly person looking for a seat on the subway.

Steven Cooney is a music education specialist who lives in Brooklyn.